chore: remove old webpack dependencies (#1032)

package.json

@@ -34,7 +34,6 @@
     "@types/request": "2.0.8",
     "@types/semver": "5.5.0",
     "@types/tmp": "0.0.33",
-    "autoprefixer": "6.5.3",
     "buffer": "5.0.6",
     "check-node-version": "^3.2.0",
     "copy-webpack-plugin": "5.0.0",
@@ -52,11 +51,8 @@
     "electron-rebuild": "1.8.6",
     "electron-settings": "3.1.4",
     "electron-updater": "2.21.4",
-    "exports-loader": "0.6.3",
-    "file-loader": "0.10.0",
     "fs-extra": "8.1.0",
     "gh-pages": "2.0.1",
-    "html-webpack-plugin": "3.2.0",
     "jasmine": "3.4.0",
     "jasmine-core": "3.4.0",
     "jasmine-node": "3.0.0",
@@ -67,7 +63,6 @@
     "node-hid": "0.7.9",
     "npm-run-all": "4.0.2",
     "nrf-intel-hex": "1.3.0",
-    "postcss-url": "8.0.0",
     "pre-commit": "1.2.2",
     "request": "2.88.0",
     "rimraf": "2.6.1",